There are multiple points of failure that can render a computer nonfunctional. For example, the data storage device, such as a hard disk drive, may be inaccessible. The storage device may be intact, but logically inaccessible because of driver errors, interface errors, or malware infection. Alternatively, the storage device may be damaged and physically inaccessible. Alternatively, other issues may cause the computer system to malfunction, including power supply faults, memory faults, system bus faults, etc. In cases where the computer is nonfunctional, it may be desirable—even urgently so—to recover and preserve user data.
Prior methods for restoring the computer system include repairing damaged components, removing hard drives and directly accessing data on the drive from other systems, and making periodic backup copies of the user data on remote or removable data storage devices. All of these methods have inherent drawbacks in terms of cost, downtime, loss of data, and loss of productivity.